The key lock of the present invention is particularly adapted to be used in conjunction with nestable/stackable plastic receptacles of the type described in U.S. Pat. Nos. 4,308,954 and 4,334,616.
As described, for example, in U.S. Pat. No. 4,308,954, receptacles are available each of which is constructed so that it may be stacked on other like receptacles when filled with products, or nested down into like receptacles when empty so as to conserve space. The receptacles described in the patent are intended primarily for use in the food industry, although they have general application in a wide variety of plants, warehouses, transportation vehicles and the like.
The receptacles may be used, for example, in transporting and displaying bakery, or other goods. For example, a plurality of the receptacles may be loaded with bakery goods at the bakery and stacked on top of one another, and they may then be transported in a stacked condition to the retail store or market. The stacked receptacles may then be positioned on the floor of the store or market so that the merchandise in the receptacles may be displayed to the purchasing public. When the receptacles are empty, they may be nested down into one another for space conservation purposes, and then returned to the bakery.
The particular nested and stackable receptacles described in the aforesaid patents are advantageous in that they are capable of being nested or stacked without the need for moving bails or other movable parts. As described in the patents, the receptacles are stacked on one another by means of interacting lugs at the top and bottom edges of each receptacle.
Many bakeries are concerned that their receptacles may be pirated and used by other bakeries in conjunction with the other bakeries' receptacles of like kind. The key lock of the present invention provides a simple means whereby the receptacles can be used only in conjunction with the receptacles from the same bakery and cannot be intermixed with the receptacles from other bakeries.